Manufactured products typically are shipped to purchasers in a container. The container protects the manufactured product from damage during handling and shipping. Containers also may be stacked for shipping and storage. Some items however are so large and heavy that the shipping container itself must have extra strength and weight to protect the enclosed product. One such product are large outboard motors in the four to eight cylinder size. Such motors are very heavy and may weigh up to eight hundred pounds or more.
Shipping of outboard motors from manufacturer to distributor or dealer presents difficult packaging problems. The problems arise because of the unusual shape of the motor and the distribution of weight in the motor. Typical outboard motors have the weight concentrated in the upper powerhead end of the motor. A relatively lightweight gear case extends longitudinally downward from the powerhead. The propellor connects to a drive shaft at the lower end of the gear case. A mounting bracket (or stern bracket) extending from the motor connects at an angle to the transom of a boat to position the motor vertically. Generally, the motor mounting bracket is located below the center of gravity of the motor. Known outboard motors swivel axially around the mounting bracket as well as tilt in the vertical plane.
The powerhead is typically enclosed in a fiberglass hood or cover. The cover typically has insufficient structural strength to serve as a bearing surface for any type of restraining or bracing members in the shipping package. The stern bracket however may be used to mount the motor in a shipping container.
A casting called an adaptor attaches the powerhead to the gear case. Generally, these castings are not sufficiently strong to withstand extremely rough handling that may be experienced during shipment. Shipping containers thus require some type of cushioning between the stern bracket and the container framework so that the motor can withstand shocks and pressures that occur if the packaged motor were knocked over or dropped from a forklift or clamp truck.
Other packaging considerations include the economic costs of transporting a number of packaged motors from the manufacturer to the distributors or dealers. Freight considerations make it desirable to keep the external dimensions of the container to a minimum. When transporting such large and bulky items, typical truckload maximum weights are almost never reached before the space in the truck trailer is filled. The shipper however is charged for the maximum amount if the trailer is full. A package which permits more containers to be loaded per truck lowers the average freight cost for shipping the motors.
In addition to the direct freight costs, other costs such as warehouse space and cost of the package itself, combine with truckload capacity, to offer practical reasons for attempting to minimize the external dimensions of the container. If it were not for these costs, the package could be made much larger for more cushioning and shock absorbing material to dampen shipping shocks and vibrations and restrict movement of the motor within the container in cases of extreme mishandling. Therefore the package must be designed to adequately cushion the motor and yet restrain internal movement within a practical package providing satisfactory protection against damage.
There are other economic reasons for packing outboard motors in sturdy shipping containers. Outboard motors for power boats may be quite expensive, and some of the larger, more powerful motors may cost more than ten thousand dollars. Shipping and handling damage may in some instances totally destroy a motor. Less serious damage to a motor, however, must be repaired before the motor may be sold or installed on a boat. The dealer or distributor receiving a damaged motor may have to wait a period of time to receive repair parts from the manufacturer. Also, the dealer or shipper incurs labor costs associated with replacing motor parts and repairing damaged motors. A container which protects a motor against shipping and handling damage may pay for itself in reduced costs associated with repairing damaged motors.
Generally it is known to mount a motor in one of two orientations for shipment in a container. First, a motor may be mounted in a horizontal position to a wood base and supported on the base by a crossbar attached to the stern bracket. A box or crate placed over the motor and attached to the base provides protection and stacking strength. A second known method is to ship the motor in a vertical position with the heavy powerhead end placed downward in a container with the gear case/propellor end up to reduce the chance of accidental tipping of the motor.
This second known configuration offers several advantages in shipping. The motors typically are of such a size that when shipped in a vertical pack, more units per truckload is possible. This results in a lower freight cost per motor unit shipped. Also, the bigger motors are more easily and safely handled by lift truck or clamp truck and require less aisle space in handling. (A squeeze or clamp truck uses hydraulically operated plattens which exert pressure of sufficient force on the sides of the container to allow the container to be lifted by the truck for moving and stacking in the warehouse.) Clamp handling equipment is often preferred to forklifts as the package then does not require the external skid boards used with a forklift pack. Eliminating the need for skid boards further reduces the cost of the package and its vertical space requirements.
The horizontal packing containers generally require more aisle space, more warehouse space, and are more difficult to handle. For example, in the absence of a fork or clamp truck which may be used to pick up and move the crated motor, it is easier to walk or manhandle a vertical pack with a relatively small area of contact with the floor than a horizontal pack where the contact area is greater. It is generally desirable that a package not only protect the motor unit during shipping, but the package itself should have sufficient topload or stacking strength to allow containers with motors to be stacked in a warehouse up to five or more units high with safety. This normally requires that the container be capable of supporting the weight of four units stacked on top. Also, a normal industry safety factor is a multiple of four times the estimated load on the bottom box in a stack.
The preferred packaging for outboard motor shipping containers requires sufficient bottom strength to withstand forklift handling while protecting the relatively weak powerhead cover. The package also requires sufficient side-to-side strength to allow handling by these squeeze or clamp trucks. Thus, the package rigidity contributes to protecting the motor, but the motor also needs cushioning to dampen vibrations or shocks to the package during handling and shipping.
Generally, many outboard motor manufacturers require a shipping container to pass a series of simulated rough handling tests before the container is approved for use in shipping. The motor is placed in the container for which approval is sought and the container is then subjected to the tests. These tests usually include dropping the container from various heights to simulate manhandling and dropping from the back of a truck; tipping the package over first with the powerhead up and then with the powerhead down to simulate accidental tipping when handling either manually or with equipment; and prolonged vibration to simulate the jostling or shaking encountered during many miles of truck or rail shipment. It is contemplated that the container of the present invention provides an outboard motor shipping container which is capable of meeting these stringent tests.
A preferred motor package is simple and relatively easy to assemble on a production line. Such simplicity and ease of assembly minimizes the labor cost involved in packaging the outboard motors for shipment. It is desirable to have few component parts and preferably the outer cartons or side wall components of the packaging collapse flat for shipment from the container manufacturer to the motor manufacturer. Thus the packaging itself preferably requires a minimum of freight costs to transport the shipping package components to the motor manufacturer, and when at the plant, requires a minimum of warehouse storage space.
The known packages previously used to ship such large outboard motors in a vertical, powerhead down configuration have not met with satisfactory results. If no material handling equipment such as a clamp or forklift truck is available, the package must be manhandled in and out of delivery trucks and around warehouses. Often this involves manhandling the package over a vertical distance between the truck and the warehouse floor. This distance may be of 48 inches or more, and sometimes the heavy motors are dropped. Thus the package requires great strength to insure side wall integrity yet provide sufficient cushioning to prevent breaking the adaptor casting or other parts not designed to take such extreme shock. The cushioning however cannot be so great as to allow the motor and motor cover to touch the inside walls of the package in the event the package is pushed over or dropped. Thus the packaging must provide sufficient shock absorbing cushioning so the motor parts will not break, yet provide sufficient restraint so the motor will not move beyond the bounds of the inside dimensions of the container when subject to such extremes in handling.
Some small motors--five or eight horsepower, for example--have been successfully packaged in styrofoam with the motor cover serving as the bearing surface for the powerhead end. In such cases, the motor cover is sufficiently strong with respect to the relatively light weight of the engine to be used safely as a bearing surface of packaging. For the much heavier, larger outboard motors such styrofoam packaging is not satisfactory. As explained previously, known packaging used to ship the large outboard motors mount the motor in a vertical, powerhead down configuration. In general, these packs have combined a standard corrugated paper board outer box with many die-cut corrugated folded and scored inner packing sheets to provide stacking strength, support for restraining movement, and side wall strength for handling by clamp trucks. One known package employs a wood board which inserts into plastic mounts or caps glued to a multi-scored corrugated pad. This forms a crossbar to which the motor may be bolted through its stern mounting bracket. This pack, however, requires over seventeen different scored corrugated sheets, and it is difficult to assemble the pack on a packing line. The many parts contribute to inventory storage and control problems, and smaller motors require different sized components than those used with larger motors. In addition, corrugated board may lose up to 50% of its stiffness and compression strength in conditions of high heat and humidity, thus making long term warehouse stacking of corrugated packages unsafe.
U.S. Pat. No. 3,136,472 issued to P. H. Waller et al. describes a container framing for shipping outboard motors in a vertical position. A wood frame is constructed around the motor, and a corrugated or solid fiber outer box is placed over this crate. No shock absorbing features are built into the wood framework and the framework does not include internal restraining pads to support the gear case and exhaust housing. The crossbar is a loose member designed for clamping onto a small motor with the side frameworks to be then placed onto the crossbar.
The Waller pack, however, cannot be unitary because if the wood framing were attached to the corrugated box, then it would be more difficult, if not impossible, to install the motor in the container. Nor could such a container fold flat, or knock-down, for more compact storage. Generally, it may be considered mandatory for a commercially produced production pack to knock-down. Without providing for padding for the gear case or exhaust housing, it is unlikely the Waller pack would pass a manufacturer's manhandling test. The motor would be free to swing about the crossbar and contact the warehouse floor in both a vertical drop and tipover. Wooden framing, lacking shock absorbing material, would transmit shock and vibrations to the motor and to the crate structure, and lead to motor damage and container damage. Significant container or frame damage may itself lead to additional motor damage. Also, the Waller packing requires a crate be assembled around the motor and then encased in a box. This is a significant assembly operation in and of itself and contributes to increased indirect costs associated with the motors.